A and B can do a job in 6 days and 12 days respectively. They began the work together but A left after 3 days. In how many days was the remaining work completed by B? MCQ with Answer and Explanation

A and B can do a job in 6 days and 12 days respectively. They began the work together but A left after 3 days. In how many days was the remaining work completed by B?
A. 3 days
B. 2 days
C. 4 days
D. 5 days
Answer: Option A
Solution (By JKSSB Mock Tests)
Total work = LCM(6, 12) = 12 units. Efficiency of A = 2, B = 1. Combined efficiency = 3 units/day. In 3 days, work done = 3 * 3 = 9 units. Remaining work = 12 - 9 = 3 units. Time taken by B to complete remaining work = 3 / 1 = 3 days.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Time and Work Questions

Question #1
A can complete a work in 21 days and B in 28 days. If they work together, the work will be completed in:
A. 17.0
B. 12.0
C. 27.0
D. 22.0

Correct Answer: Option B


Explanation:
Combined rate = 1/21 + 1/28. Required time = 12.0 days.

This question belongs to: Maths Time and Work
Question #2
A can do a work in 9 days and B in 23 days. In how many days will they complete 75% of the work together?
A. 9.85
B. 7.35
C. 12.35
D. 4.85

Correct Answer: Option D


Explanation:
Combined time for full work multiplied by 0.75 = 4.85 days.

This question belongs to: Maths Time and Work
Question #3
A is thrice as efficient as B. Working together, they can complete a piece of work in 18 days. In how many days can A alone complete the work?
A. 54 days
B. 72 days
C. 24 days
D. 36 days

Correct Answer: Option C


Explanation:
Let B's efficiency = 1, then A's efficiency = 3. Combined efficiency = 3 + 1 = 4. Total work = 18 * 4 = 72 units. Time taken by A alone = 72 / 3 = 24 days.

This question belongs to: Maths Time and Work